try this Pimp50, i've done a tute on setting valve clearances with pics from start to finish... pretty self explanatory mate, if you get real stuck, my shed's open to local MR members for tool time and maintenance tutorial etc etc... PM me if you wanna book a time...
http://www.miniriders.com.au/motor-tutorials/24965-how-set-valve-clearances-horizontal-engines.html
http://www.miniriders.com.au/motor-tutorials/24965-how-set-valve-clearances-horizontal-engines.html